While lifts are known that extend off the back of a truck by folding down or by arcuately extending outward and down from the back of a truck. These lifts fail to provide for use when space behind a truck is limited, are bulky additions to the truck, and do not provide additional floor space while enclosing the lift components within the enclosure of the cargo area.
Typically, trailers and vehicles with a trailer or enclosure for hauling cargo are arranged to haul cargo within the trailer and atop a trailer floor. One such arrangement is found in a delivery truck, which includes a vertically movable lift gate, which swings down and extends rearwardly from the end of the trailer floor. Cargo is either loaded onto or off the rear lift gate and either elevated or lowered for pick up or delivery of the cargo. However, in inclement weather, the operator and the cargo may be exposed to rain or snow by being outside of the confines of the trailer. Moreover, extra room behind the, trailer-is required to accommodate the length of the lift gate and additional space to load and unload cargo therefrom.
A number of prior art systems have been developed which, in part, address this limiting aspect of the above delivery trucks. U.S. Pat. No. 4,236,747 issued Dec. 2, 1980 to Ratliff discloses a transport vehicle for medium-sized route delivery of goods. The versatile design allows for removability of the central partition in each cargo bay and adjustability of the position of the floor. A delivery truck body or trailer, which is convertible between being arranged for side loading at ground level or rear loading at dock height, is disclosed in U.S. Pat. No. 4,659,132 to Day.
Price teaches a double drop trailer with lifts therein in U.S. Pat. No. 5,092,721. A first lift comprises upper and lower platforms rigidly interconnected one to another, the second lift located in the rear section.
Three U.S. patents to Greenlaw, et al., U.S. Pat. Nos. 5,915,913, 6,328,525 and 6,474,446, teach delivery vehicles with multi-tier storage and elevator assemblies installed therein. Substantially continuous side access door provide total exterior access to the lowermost tier of cargo in the '525 patent, the '913 patent teaching elevator assemblies for multi-tier storage. The '446 patent teaches a framing system that reduces structural requirements of side walls and floors, permitting multiple Side access ports and reduced floor thickness to permit easier access from the pavement.
Recently issued U.S. Pat. No. 7,114,905 to Dibdin teaches methods and an apparatus for optimizing use of storage space in a trailer. The apparatus provides a loading apparatus for the trailer having a platform movable relative to the floor of the trailer to facilitate loading of goods.
Published application 2003/0147734 to Adams discloses a goods handling system for a vehicle or railway trailer which allows the level of access to all areas of the trailer to be improved.
An under ride is a cross member positioned below a vehicle trailer and the ground, providing a safety barrier which keeps other vehicles from encroaching under the vehicle.
Federal Motor Vehicle Safety Standard No. 224, Rear Impact Protection, requires most trailers and semi-trailers weighing over 10,000 pounds to be fitted at the rear with a rear impact (underside) guard meeting the requirements of Standard No. 223, Rear impact guards (49 CFR 571.223 and 571.224) published on Jan. 24, 1996 at 61 FR 2004).
Concerns were expressed about compatibility of undersides in conjunction with trailers and semi-trailers equipped with equipment such as liftgates. Concerns about certain incompatible equipment led NHTSA to exclude “special purpose vehicles” from the requirements of the standard. A special purpose vehicle is defined in 84 of Federal Motor Vehicle Safety Standard No. 224 as, “a trailer or semi-trailer having work-performing equipment that, while the vehicle is in transit, resides in or moves through the area that could be occupied by the horizontal member of the rear underside guard, as defined by S5.1.1 through S5.1.3. If any work-performing equipment is mounted in the guard zone, the vehicle is excluded regardless of when and how the equipment is used.
Undersides are valuable safety devices that are excluded on trailers or semi-trailers that include equipment such as liftgates. An underside design that is compatible with equipment such as liftgates is desired.
None of the known lifts provide vertically movable cargo within the confines of a trailer enclosure. Additional space is required rearwardly of the trailer for most of the known systems. Additionally, movable side cargo-receiving lifts are capable of being used for floor space for hauling Cargo.